Electrode sheet manufacturing apparatus and electrode sheet manufacturing method

Abstract

The invention provides an electrode sheet manufacturing apparatus and an electrode sheet manufacturing method. The electrode sheet manufacturing apparatus manufactures an electrode sheet having a current collector comprising a long metal foil, an unformed portion, and an electrode active material layer. The electrode sheet manufacturing device comprises a conveying device, a supporting roller, a pressing roller and a driving device. The support roller supports the first surface of the electrode sheet in the width direction. The pressing roller is disposed on the second surface of the electrode sheet so as to face the support roller. The pressing roller includes a shaft portion and a rubber portion. The rubber portion is wound around the outer peripheral surface of the shaft portion at least in a region in contact with the unformed portion. The thickness of the rubber portion at a position overlapping the outer end of the unformed portion is thinner than the thickness of the rubber portion in a region further inward than the position overlapping the outer end.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrode sheet manufacturing apparatus and a manufacturing method of an electrode sheet. BACKGROUND

[0002] In Japanese Patent Application Publication No. 2023-36089, a manufacturing method of an electrode is disclosed, which includes a preparation step of preparing an electrode sheet; a coated portion pressing step of pressing a coated portion in a thickness direction; and an uncoated portion pressing step of pressing an uncoated portion in the thickness direction. In the uncoated portion pressing step, the uncoated portion is pressed by a pair of elastic rollers in the thickness direction in the uncoated portion pressing step having a shaft body and an elastic body covering the shaft body. If the manufacturing method is used, the uncoated portion can be extended while the breakage is suppressed.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2023-36089

[0004] In a case where the current collector of the electrode sheet is elongated using a roller provided with a rubber portion on an outer peripheral surface, the ease of elongation of the current collector differs depending on the position of the rubber portion. If the elongation of the current collector is not uniform, the quality of the electrode sheet can be affected. SUMMARY

[0005] The electrode sheet manufacturing apparatus disclosed herein is a manufacturing apparatus of an electrode sheet. The electrode sheet has a current collector, an unformed portion, and an electrode active material layer. The current collector is composed of a long metal foil. The unformed portion is provided at a predetermined position in the width direction of the current collector in the length direction. The electrode active material layer is formed at a portion other than the unformed portion in the current collector. The electrode sheet manufacturing apparatus has a conveying apparatus, a support roller, a pressing roller, and a driving apparatus. The conveying apparatus conveys a long electrode sheet along a predetermined conveying path. The support roller is disposed at the conveying path. The support roller supports a first surface of the electrode sheet conveyed along the conveying path in the width direction. The pressing roller is disposed in opposition to the support roller at a second surface of the electrode sheet. The driving apparatus causes the pressing roller to press toward the support roller with the electrode sheet interposed therebetween. The electrode sheet has a current collector and an electrode active material layer. The current collector is composed of a metal foil. The electrode active material layer is formed on the current collector. An unformed portion, which is not coated with the electrode active material layer, is provided at an end portion of the electrode sheet. The pressing roller has a shaft portion and a rubber portion. The rubber portion is wound around an outer peripheral surface of the shaft portion at least in a region in contact with the unformed portion. The thickness of the rubber portion at a position overlapping an outer end of the unformed portion is thinner than the thickness of the rubber portion at a region inward of the position overlapping the outer end. According to the electrode sheet manufacturing apparatus, the elongation of the current collector of the electrode sheet becomes uniform, and the quality of the electrode sheet can be easily improved. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a flowchart of the manufacturing by the electrode sheet manufacturing apparatus 1.

[0007] Figure 2 is a schematic view of the electrode sheet 10.

[0008] Figure 3 is a schematic side view of the electrode sheet manufacturing apparatus 1.

[0009] Figure 4 is a front view of the roll press 50.

[0010] Figure 5 is Figure 4 is a sectional view of the A-A section shown.

[0011] Figure 6 is a schematic view showing the positional relationship of the electrode sheet 10, the support roll 60, and the press roll 70.

[0012] Figure 7 is a schematic view showing the relationship between the thickness of the rubber and the amount of deformation.

[0013] Figure 8 is a schematic view of the roll press 150 involved in the other embodiment.

[0014] Figure 9 is a schematic view of the roll press 250 involved in the other embodiment.

[0015] Figure 10 is a schematic view of the roll press 350 involved in the other embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, one embodiment of the technology disclosed herein will be described with reference to the drawings. Of course, the embodiment described here is not intended to particularly limit the present application. The drawings are schematically depicted, and do not necessarily reflect the actuality. In addition, the same reference numerals are appropriately assigned to components, sites that play the same role, and the repeated description is appropriately omitted.

[0017] Figure 1 is a flowchart of the manufacturing by the electrode sheet manufacturing apparatus 1. As Figure 1 indicated, in the manufacturing by the electrode sheet manufacturing apparatus 1, the preparation processes S1 to S5, the roll pressing process S6, and the formal pressing process S7 are included. In this embodiment, in the preparation processes, the conveying process S1, the metering process S2, the mixing process S3, the coating process S4, and the drying process S5 are included. However, other processes can be included in the manufacturing by the electrode sheet manufacturing apparatus 1.

[0018] <Electrode sheet manufacturing apparatus 1>

[0019] In the electrode sheet manufacturing apparatus 1, the electrode sheet 10 (refer to Figure 2The electrode sheet 10 is manufactured using the electrode body housed within the energy storage device. An energy storage device is a device capable of repeated charging and discharging; it encompasses not only batteries (chemical batteries) such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, but also capacitors (physical batteries) such as electric double-layer capacitors. Hereinafter, as an example, the electrode sheet manufacturing apparatus 1 for manufacturing the electrode sheet 10 will be described, along with the structure of the electrode sheet 10 used in a lithium-ion secondary battery.

[0020] <Electrode Plate 10>

[0021] Figure 2 This is a schematic diagram of electrode plate 10. (As shown...) Figure 2 As shown, the electrode sheet 10 includes a current collector 12 and an electrode active material layer 14. The electrode sheet 10 may also include a protective layer 16. The current collector 12 is a component made of metal foil. The current collector 12 is a long strip-shaped metal component. As the current collector 12, a metal material with the required conductivity can be used. As the positive current collector, aluminum, aluminum alloy, etc., can be used, for example. As the negative current collector, copper, copper alloy, etc., can be used, for example. The electrode active material layer 14 is coated at a predetermined position in the current collector 12. The electrode active material layer 14 is formed on at least one side of the strip-shaped current collector 12. In this embodiment, the electrode active material layer 14 is formed on both sides of the current collector 12. The electrode active material layer 14 is a layer containing electrode active material. As the positive electrode active material, lithium transition metal composite oxide, for example, can be used. As the negative electrode active material, carbon materials, silicon-based materials, and their mixed oxides, for example, can be used. The electrode active material layer may also contain additives other than electrode active materials such as binders and conductive materials.

[0022] The electrode sheet 10 is formed by applying to the current collector 12 an electrode mixture slurry that becomes the electrode active material layer 14 and drying it. The current collector 12 is provided with an uncoated portion 12a and a coated portion 12b. The uncoated portion 12a is a portion of the current collector 12 that is not coated with the electrode active material layer 14 and the protective layer 16. The uncoated portion 12a is provided at a predetermined position in the width direction of the electrode sheet 10 in the length direction. The uncoated portion 12a is one example of an unformed portion that is provided at a predetermined position in the width direction of the current collector 12 in the length direction as a portion that is not formed with the electrode active material layer 14 and the protective layer 16. The electrode active material layer 14 is formed at a portion of the current collector 12 other than the uncoated portion 12a. Here, the electrode active material layer 14 is formed by being applied to a portion of the current collector 12 other than the uncoated portion 12a. In the present embodiment, the uncoated portion 12a is provided at both ends in the width direction of the electrode sheet 10. The coated portion 12b is disposed between the uncoated portions 12a at both ends of the electrode sheet 10. The electrode mixture slurry is applied to the coated portion 12b. Thus, the electrode active material layer 14 is formed at the coated portion 12b of the current collector 12. That is, the electrode active material layer 14 is disposed between the uncoated portions 12a at both ends in the width direction of the electrode sheet 10.

[0023] The protective layer 16 is a layer that is formed along the electrode active material layer 14. The protective layer 16 is provided along the electrode active material layer 14 on the positive electrode side. The protective layer 16 is, for example, a layer that has a higher electrical resistance than the electrode active material layer 14. The protective layer 16 contains, for example, inorganic particles and a resin (binder). As the inorganic particles, for example, inorganic oxides such as alumina, boehmite, magnesia, silica, titania, and the like can be given. As the resin (binder), for example, polyvinylidene fluoride (PVdF) and the like can be given. Alternatively, the protective layer 16 can be a layer composed of a resin. If necessary, a conductive material such as a carbon material can also be contained in the protective layer 16. By providing the protective layer 16, it is possible to improve the effect of suppressing short-circuiting in the electrode body. Furthermore, the protective layer 16 is not necessarily provided to the electrode sheet 10. In the case where the protective layer 16 is provided to the electrode sheet 10, the width of the protective layer 16 can be, for example, 1 / 8 or more and 1 / 3 or less (for example, 1 / 6 or more and 1 / 4 or less) of the width of the uncoated portion 12a.

[0024] For example, the thickness of the protective layer 16 is smaller than the thickness of the electrode active material layer 14. If the thickness of the protective layer 16 is smaller than the thickness of the electrode active material layer 14, it is possible to improve the flexibility of the corner portion of the current collector 12 at the end portion in the long direction. The thickness of the protective layer 16 is not particularly limited, but can be, for example, 0.3 times or more and 0.7 times or less (for example, 0.4 times or more and 0.6 times or less) of the thickness of the electrode active material layer 14.

[0025] 〈Conveying device 17〉

[0026] In Figure 1 the transport process S1, the electrode sheet 10 is transported. Figure 3 is a schematic side view of the electrode sheet manufacturing apparatus 1. The transport process S1 can be implemented by a transport device 17. As Figure 3 illustrated, the transport device 17 transports the long electrode sheet 10. For the transport device 17, for example, a motor is used. In order to be able to transport the electrode sheet 10 at a predetermined transport speed, the transport device 17 is provided with an unwinding roller 17a and a winding roller 17b. The unwinding roller 17a is disposed on the upstream side of the transport direction of the calender 50. The winding roller 17b is disposed on the downstream side of the transport direction of the calender 50. However, the transport device 17 is not limited to the unwinding roller 17a and the winding roller 17b. For example, the transport device 17 can be provided with other rollers in addition to the unwinding roller 17a and the winding roller 17b. The electrode sheet 10 is transported along a predetermined transport path 18 by the transport device 17.

[0027] 〈Measurement process S2, mixing process S3, coating process S4, drying process S5〉

[0028] In Figure 1 the measurement process S2, the raw material of the electrode active material layer 14 (refer to Figure 2 ) is measured. This measurement can be implemented, for example, by a balance, a measurement device (not illustrated) having a load cell, or the like. The measured raw material of the electrode active material layer 14 is mixed in the mixing process S3. The mixing process S3 can be implemented by a mixing device (not illustrated). The raw material of the electrode active material layer 14 made into a slurry by the mixing device is coated on the current collector 12 (refer to Figure 2 ) by the coating process S4. The coating process S4 can be implemented, for example, by a slot coater, a gravure coater, a die coater, a comma coater, or the like. In the drying process S5, the raw material of the electrode active material layer 14 made into a slurry which has been coated is dried. The drying process S5 can be implemented, for example, by a drying device (not illustrated) which generates hot air or infrared rays.

[0029] 〈Calendering process S6〉

[0030] In the calendering process S6, the electrode sheet 10 is pressed. The calendering process S6 can be implemented by the calender 50 illustrated in Figure 3 . As Figure 3 illustrated, the electrode sheet 10 is pressed by the calender 50 in the middle of the transport path 18. The electrode sheet 10 is fed by the unwinding roller 17a. The electrode sheet 10 which has been pressed by the calender 50 is wound by the winding roller 17b. The electrode sheet manufacturing apparatus 1 is provided with a control device 100 which controls the unwinding roller 17a, the winding roller 17b, and the calender 50.

[0031] <roll press 50>

[0032] Figure 4 is a front view of the roll press 50. Here, the roll press 50 according to the present embodiment is a device that presses the uncoated portion 12a of the electrode sheet 10 with a rubber roller before or after the coated portion 12b is pressed. If the uncoated portion 12a is pressed with the rubber roller, the uncoated portion 12a receives a reaction force of elastic deformation and compression deformation of the rubber roller, thereby being pressed and stretched at the portion pressed by the roller. As a result, it is possible to suppress the breakage of the uncoated portion 12a and extend the uncoated portion 12a. The device that presses the uncoated portion 12a of the electrode sheet 10 with the rubber roller according to this function can be appropriately referred to as an EPS (Elasticity Powered Stretching) device. The electrode sheet manufacturing device 1 can also have a device that presses the coated portion 12b in addition to the roll press 50.

[0033] The roll press 50 has a support roller 60, a press roller 70, and a press pressure adjustment mechanism 80.

[0034] <support roller 60>

[0035] The support roller 60 is disposed on the conveying path 18 (refer to Figure 3 ). The support roller 60 supports the lower surface 10D of the electrode sheet 10 conveyed along the conveying path 18 in the width direction of the electrode sheet 10. The lower surface 10D is one example of the first surface in the present application. The support roller 60 is disposed below the press roller 70. The support roller 60 is a rubber roller that presses the uncoated portion 12a of the electrode sheet 10 together with the press roller 70. The support roller 60 has a main body portion 61 and two shaft portions 66.

[0036] Figure 5 is a cross-sectional view of the A-A cross section shown in Figure 4 . In Figure 5 , a case where the uncoated portion 12a is pressed by the support roller 60 and the press roller 70 is illustrated. As shown in Figure 5 , the main body portion 61 of the support roller 60 has a shaft portion 62 and a rubber portion 63. The shaft portion 62 is made of metal. The material that forms the shaft portion 62 is not particularly limited, but is, for example, a material with relatively high hardness such as SUS304 (stainless steel material). The rubber portion 63 is disposed so as to cover at least the outer peripheral surface of the shaft portion 62. The material that forms the rubber portion 63 is, for example, nitrile rubber (NBR). The support roller 60 presses the uncoated portion 12a of the electrode sheet 10 by the rubber portion 63.

[0037] The support roller 60 is driven by the roll driving device 84 (refer to Figure 4The support roller 60 rotates in a specified direction. In this embodiment, the support roller 60 rotates in a specified direction. Figure 5 The direction of arrow R1 shown rotates. At this time, observing the attached diagram, the electrode plate 10 is conveyed from left to right. That is, Figure 5 The left side in the middle is the upstream side of the conveying direction. Figure 5 The right side of the middle section is the downstream side of the conveying direction.

[0038] like Figure 4 As shown, two shaft portions 66 are inserted into the main body portion 61. The two shaft portions 66 are inserted into the shaft portion 62 of the main body portion 61 (see reference). Figure 5 The two shaft portions 66 extend to the outer side of the support roller 60 in the axial direction. In addition, although not shown in the figure, the two shaft portions 66 are equipped with bearings, gap screws for adjusting the gap between the support roller 60 and the pressing roller 70, etc.

[0039] <Pressing roller 70>

[0040] like Figure 5 As shown, the pressing roller 70 is arranged on the upper surface 10U of the electrode sheet 10 in a manner opposite to the support roller 60. The pressing roller 70 is configured such that, except for the coating portion 12b in the electrode sheet 10 (see reference...), Figure 2 Apart from the uncoated portion 12a, the uncoated portion 12a is clamped between the pressing roller 70 and the support roller 60. The upper surface 10U is an example of the second surface in this invention. The axial center positions of the pressing roller 70 and the support roller 60 are aligned vertically. Figure 4 As shown, the pressing roller 70 is a rubber roller that, together with the support roller 60, presses the uncoated portion 12a of the electrode sheet 10. The pressing roller 70 is not positioned above the coated portion 12b of the electrode sheet 10. In this embodiment, as described above, the uncoated portion 12a of the electrode sheet 10 is located at both ends in the width direction of the electrode sheet 10. Therefore, as... Figure 4 As shown, the pressing rollers 70 are respectively disposed above the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction. However, if there is only one uncoated portion 12a, there may be only one pressing roller 70. The pressing roller 70 disposed on the left is also referred to as pressing roller 70L, and the pressing roller 70 disposed on the right is also referred to as pressing roller 70R. However, in the description corresponding to either pressing roller 70L or 70R, the name pressing roller 70 is appropriately used. The pressing roller 70 has a main body portion 71 (see reference 70L). Figure 5 ) and two shaft parts 76.

[0041] like Figure 5As shown, the main body 71 of the pressing roller 70 includes a shaft portion 72 and a rubber portion 73. The shaft portion 72 is made of metal. The material forming the shaft portion 72 is not particularly limited, but it can be, for example, a material with relatively high hardness such as SUS304 (stainless steel). The rubber portion 73 is arranged to cover at least the outer peripheral surface of the shaft portion 72. The material forming the rubber portion 73 is not particularly limited, but it can be, for example, nitrile rubber (NBR). The pressing roller 70 presses the uncoated portion 12a of the electrode sheet 10 through the rubber portion 73.

[0042] like Figure 4 As shown, two shaft portions 76 are inserted into the main body portion 71. The two shaft portions 76 are inserted into the shaft portion 72 of the main body portion 71 (see reference). Figure 5 The two shaft portions 76 extend to the outer side of the axial direction of the two pressing rollers 70. Furthermore, although not shown in the figure, the two shaft portions 76 are equipped with bearings, clearance screws for adjusting the gap between the support roller 60 and the pressing roller 70, etc.

[0043] like Figure 5 As shown, when the support roller 60 and the pressing roller 70 clamp the electrode sheet 10 and the support roller 60 rotates in the direction of arrow R1, the pressing roller 70 receives a force rotating in the direction of arrow R2 via the electrode sheet 10. Alternatively, when the electrode sheet 10 is not positioned and the support roller 60 is in contact with the pressing roller 70, the pressing roller 70 receives a force rotating in the direction of arrow R2 due to the force of the rotation of the support roller 60. Therefore, the pressing roller 70 rotates in the direction of arrow R2. That is, the pressing roller 70 rotates driven by the rotation of the support roller 60.

[0044] like Figure 4 As shown, the pressing pressure adjustment mechanism 80 includes a pressure cylinder 81, a roller bearing seat 82, a cylinder drive device 83, a roller drive device 84, and a support part 85.

[0045] The pressure cylinder 81 presses the pressing roller 70 against the support roller 60. One pressure cylinder 81 is positioned on each side of the pressing roller 70, slightly outward from both ends. Figure 4 In this embodiment, the pressure cylinder 81 positioned to the left of the electrode plate 10 is also referred to as pressure cylinder 81L, and the pressure cylinder 81 positioned to the right of the electrode plate 10 is also referred to as pressure cylinder 81R. However, when describing the commonalities between pressure cylinders 81L and 81R, it is also referred to as pressure cylinder 81. In this embodiment, pressure cylinder 81 is a pneumatic cylinder. Pressure cylinder 81 includes a rod 81a. Rod 81a is connected to roller bearing seat 82. Roller bearing seat 82 is a component that supports the two shaft portions 76 of the pressing roller 70 so that they can rotate. If pressure cylinder 81 drives rod 81a to descend, pressing roller 70 descends. If pressure cylinder 81 drives rod 81a to rise, pressing roller 70 rises.

[0046] The cylinder drive device 83 is a device that presses the pressing roller 70 against the support roller 60 across the electrode sheet 10. The cylinder drive device 83 is one example of a drive device in this invention. The cylinder drive device 83 is connected to the pressure cylinder 81. The cylinder drive device 83 drives the pressure cylinder 81. This causes the rod 81a of the pressure cylinder 81 to rise and fall. In this embodiment, the cylinder drive device 83 is configured to drive the pressure cylinders 81L and 81R independently. That is, it independently drives the pressing rollers 70 positioned above the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction. The cylinder drive device 83 and the control device 100 (see reference...) Figure 3 )connect.

[0047] The roller drive device 84 is connected to the support roller 60. The roller drive device 84 is a device that rotates the support roller 60. In this embodiment, the roller drive device 84 causes the support roller 60 to rotate along... Figure 5 The rotation is in the direction of arrow R1 shown. The structure of the roller drive device 84 is not particularly limited, but it may consist of, for example, an electric motor, gears, etc. The roller drive device 84 and the control device 100 (see reference) Figure 3 (Connection). Additionally, the roller drive device 84 can also rotate the pressing roller 70.

[0048] The support part 85 is a component that supports the support roller 60. The support part 85 supports the two shaft parts 66 of the support roller 60.

[0049] The following description will focus on the support roller 60 and pressing roller 70 that constitute the roller press 50, as well as the pressed electrode sheet 10.

[0050] Figure 6 This is a schematic diagram showing the positional relationship between the electrode sheet 10, the support roller 60, and the pressing roller 70. Figure 6 In the diagram, the electrode sheet 10, the support roller 60, and the pressing roller 70 are hypothetically shown in a separate manner. Figure 6 The image shows a cross-section of the electrode plate 10, the support roller 60, and the right-side pressing roller 70R. The structure of the left-side pressing roller 70L is the same as that of the right-side pressing roller 70R, so detailed descriptions are omitted.

[0051] <Support Roller 60>

[0052] like Figure 6 As shown, the support roller 60 (the main body 61 in this embodiment) includes a shaft portion 62 and a rubber portion 63. The outer diameter of the support roller 60 is approximately constant.

[0053] <Shaft 62>

[0054] The shaft portion 62 is a generally cylindrical component extending along the width direction of the electrode sheet 10. In this embodiment, the diameter of the shaft portion 62 is approximately constant. A rubber portion 63 is wound around the outer peripheral surface 62d of the shaft portion 62. The thickness of the rubber portion 63 is approximately constant except at both ends along the shaft of the support roller 60.

[0055] <Rubber Section 63>

[0056] The rubber portion 63 is formed in a generally cylindrical shape. The inner peripheral surface 63d of the rubber portion 63 corresponds to the outer peripheral surface 62d of the shaft portion 62. The inner diameter of the rubber portion 63 is the same as the outer diameter of the shaft portion 62. In this embodiment, the inner diameter of the rubber portion 63 and the outer diameter of the shaft portion 62 are the same and are approximately constant. The electrode sheet 10 is supported by the outer peripheral surface 63f of the rubber portion 63. The uncoated portion 12a of the electrode sheet 10 is pressed by the pressing roller 70. The thickness of the rubber portion 63 is not particularly limited. In this embodiment, the thickness of the rubber portion 63 is set to be the same as the thickness of the thick portion 73a described later. For example, the thickness of the rubber portion 63 can be set to be at least 0.9 times and less than 1.1 times the thickness of the thick portion 73a.

[0057] <Pressing roller 70>

[0058] The pressing roller 70 (in this embodiment, the main body 71) includes a shaft portion 72 and a rubber portion 73. The length (dimension along the shaft) of the pressing roller 70 is shorter than the length of the support roller 60. Therefore, the electrode sheet 10 is partially clamped and pressed by the support roller 60 and the pressing roller 70. The pressing roller 70 is configured to press the uncoated portion 12a in the electrode sheet 10. The length of the pressing roller 70 is longer than the width of the uncoated portion 12a. In this embodiment, the length of the pressing roller 70 can be more than 1.1 times and less than 1.8 times the width of the uncoated portion 12a.

[0059] The pressing roller 70 is positioned to press the uncoated portion 12a. The position of the pressing roller 70 can be set according to the size of the coated portion 12b of the electrode sheet 10. In this embodiment, the inner side of the pressing roller 70 (in...) Figure 6 In the embodiment shown, the end face 70a (left side) is located outside the electrode active material layer 14 in the coating portion 12b of the electrode sheet 10. Figure 6 In the embodiment shown, the end 14a (right side) is located slightly inward. The outer end face 70b of the pressing roller 70 is located further outward than the outer end 12a1 of the uncoated portion 12a of the electrode sheet 10.

[0060] <Shaft 72>

[0061] The shaft portion 72 has a cylindrical portion 72a, a stepped portion 72b, and an inclined portion 72c.

[0062] The cylindrical portion 72a is a substantially cylindrical portion having a rotation axis set in a manner substantially parallel to the rotation axis of the press roller 70. The diameter of the cylindrical portion 72a is substantially constant. The cylindrical portion 72a is provided from the inner side of the shaft portion 72 (the end surface 70a side) toward the outer side.

[0063] The stepped portion 72b is a portion having a diameter larger than that of the cylindrical portion 72a. The stepped portion 72b is provided on the outer side of the shaft portion 72 (the end surface 70b side). The stepped portion 72b is provided at least at a position overlapping with the outer end 12al of the uncoated portion 12a of the electrode sheet 10. The stepped portion 72b extends from the outer end 12al of the uncoated portion 12a toward the outer side.

[0064] The inclined portion 72c is a portion connecting the cylindrical portion 72a and the stepped portion 72b. The inclined portion 72c is a portion inclined from the cylindrical portion 72a toward the stepped portion 72b. In this embodiment, the inclined portion 72c is inclined in a manner that the diameter increases from the cylindrical portion 72a toward the stepped portion 72b. Further, the inclined portion 72c is not necessarily provided on the shaft portion 72. The rubber portion 73 is wound around the outer peripheral surface 72d of the shaft portion 72.

[0065] 〈Rubber portion 73〉

[0066] The rubber portion 73 is wound around the outer peripheral surface 72d of the shaft portion 72 at least in a region in contact with the uncoated portion 12a. The inner diameter of the rubber portion 73 corresponds to the outer diameter of the shaft portion 72. In this embodiment, the rubber portion 73 covers the entire outer peripheral surface (side peripheral surface) 72d of the shaft portion 72. In other words, the inner peripheral surface 73d of the rubber portion 73 follows the outer peripheral surface 72d of the shaft portion 72. The length of the rubber portion 73 is substantially the same as the length of the shaft portion 72. The rubber portion 73 is formed in a substantially cylindrical shape. The outer diameter of the rubber portion 73 is substantially constant. In this embodiment, the rubber portion 73 has a thick portion 73a, a thin portion 73b, and an inclined portion 73c. The thick portion 73a is wound around the cylindrical portion 72a of the shaft portion 72. The thin portion 73b is wound around the stepped portion 72b of the shaft portion 72. The inclined portion 73c is wound around the inclined portion 72c of the shaft portion 72.

[0067] The thick portion 73a is thicker than the thin portion 73b. Although not particularly limited, the thickness of the thin portion 73b can be set to a degree of 1 mm or more and 30 mm or less. The thickness of the thick portion 73a can be set to a degree of 2 times or more and 3 times or less of the thickness of the thin portion 73b. The inclined portion 73c is inclined in a manner that it becomes thinner from the thick portion 73a toward the thin portion 73b. The sum of the outer diameter of the cylindrical portion 72a and the thickness of the thick portion 73a is substantially the same as the sum of the outer diameter of the stepped portion 72b and the thickness of the thin portion 73b. The sum of the outer diameter of the inclined portion 72c and the thickness of the inclined portion 73c is substantially constant in the axial direction of the press roller 70. Therefore, the diameter of the press roller 70 is substantially constant.

[0068] As described above, the stepped portion 72b overlaps with the outer end 12a1 of the uncoated portion 12a. A thin portion 73b of the rubber portion 73 is wound around the outer peripheral surface of the stepped portion 72b. As a result, the thickness of the rubber portion 73 at the position where it overlaps with the outer end 12a1 of the uncoated portion 12a is thinner than the thickness of the rubber portion 73 in the region inside the position where it overlaps with the outer end 12a1.

[0069] In this embodiment, the end portion of the rubber portion 73 in the width direction is chamfered, forming a chamfered portion 73e at the end. The chamfered portion 73e is a portion at the end that is recessed compared to the outer peripheral surface 73f. The chamfered portion 73e has a C-shaped chamfer, where the corner of the rubber portion 73 is cut in a generally straight line. Furthermore, the shape of the chamfered portion 73e is not particularly limited; for example, it may also have an R-shaped chamfer. The chamfered portion 73e is continuously formed in the circumferential direction. The chamfered portion 73e is provided at a position overlapping the boundary between the electrode active material layer 14 and the protective layer 16 of the electrode sheet 10. Although not particularly limited, the chamfered portion 73e can be formed towards the inward from a position slightly away from the end portion 14a of the electrode active material layer 14, so as not to over-compress the electrode active material layer 14 during rolling. In this embodiment, the chamfered portion 73e is formed towards the inward from a position approximately 2 mm outward from the end portion 14a of the electrode active material layer 14.

[0070] The electrode sheet manufacturing apparatus 1 according to this embodiment has been described above. Next, the operation of pressing the uncoated portion 12a of the electrode sheet 10 by the roller press 50 will be described.

[0071] First, such as Figure 4 As shown, control device 100 (refer to) Figure 3 The cylinder drive device 83 and the roller drive device 84 are controlled. The cylinder drive device 83 lowers the rod 81a of the pressure cylinder 81. The cylinder drive device 83 lowers the rod 81a to a predetermined position. As a result, the pressing roller 70 descends. At the same time, the roller drive device 84 rotates the support roller 60. In this embodiment, as... Figure 5 As shown, the roller drive device 84 rotates the support roller 60 in the direction of arrow R1. If the pressing roller 70 descends, the portion of the uncoated portion 12a held by the support roller 60 and the pressing roller 70 is compressed.

[0072] At this time, as Figure 6As shown, the electrode sheet 10 is pressed by the outer peripheral surface 63f of the rubber portion 63 of the support roller 60 and the outer peripheral surface 73f of the rubber portion 73 of the press roller 70. The rubber portion 73 is formed in the press roller 70 so as to extend from the inner side end surface 70a to the outer side end surface 70b. By providing the rubber portion 73 in the region in contact with the uncoated portion 12a, the uncoated portion 12a is pressed so as to extend over the entire width of the uncoated portion 12a. Thus, the uncoated portion 12a is extended while passing between the support roller 60 and the press roller 70. At this time, the outer peripheral surface 73f of the rubber portion 73 abuts against the protective layer 16. By forming a chamfer portion 73e in the rubber portion 73 at a position overlapping the end portion 14a of the electrode active material layer 14, the lower surface 14f is less likely to interfere with the electrode active material layer 14 even when the protective layer 16 and the uncoated portion 12a are compressed.

[0073] If the uncoated portion 12a is pressed and extended in the roll pressing step S6, the coated portion 12b is then calendered in the official pressing step S7.

[0074] (Official pressing step S7)

[0075] In the official pressing step S7, the coated portion 12b in the electrode sheet 10 is pressed. In the present embodiment, the coated portion 12b is calendered in the official pressing step S7. The official pressing step S7 can be implemented by Figure 3 the roll press 90 shown in FIG. 6. As shown in FIG. 6, the roll press 90 is provided in the conveyance path 18 on the downstream side of the roll press 50. The roll press 90 has one pair of calender rollers 91, 92. The calender rollers 91, 92 are each a substantially cylindrical roller extending in the width direction of the coated portion 12b (see FIG. 2) of the electrode sheet 10. The calender rollers 91, 92 are each longer than the width of the coated portion 12b. Figure 3 Figure 4

[0076] The pair of calender rollers 91, 92 are opposed to each other with a gap therebetween as required. The gap between the pair of calender rollers 91, 92 can be adjusted by a not-shown drive device (e.g., a cylinder device, etc.). The gap between the pair of calender rollers 91, 92 can be set to be narrower than the thickness of the electrode sheet 10 (in the present embodiment, the total thickness of the current collector 12 and the electrode active material layers 14 formed on both surfaces). For example, the pair of calender rollers 91, 92 can be driven in a state of contact. Figure 2

[0077] ​​​1The pair of calender rolls 91, 92 can be driven to rotate by driving devices (e.g., electric motors, etc.) not shown. The pair of calender rolls 91, 92 can be driven to rotate in cooperation with the conveyance of the electrode sheet 10. For example, the pair of calender rolls 91, 92 can be driven to rotate in such a manner that the peripheral speed of the peripheral surfaces matches the conveyance speed of the electrode sheet 10. Thereby, the electrode sheet 10 is conveyed while passing between the pair of calender rolls 91, 92. At this time, the electrode sheet 10 is conveyed while the thickest electrode active material layer 14 in the electrode sheet 10 is compressed by the pair of calender rolls 91, 92. If the electrode active material layer 14 is compressed, the current collector 12 of the portion to which the electrode active material layer 14 is applied is also pressurized, and as a result, the portion of the current collector 12 is stretched. At this time, the pair of calender rolls 91, 92 do not compress the protective layer 16 and the uncoated portion 12a, which are thinner than the current collector 12.

[0078] Further, the official pressing step S7 is not limited to the above-described embodiment as long as the electrode active material layer 14 is compressed. In addition, the official pressing step S7 can be performed before the roll pressing step S6. In this case, the roll press 90 can be provided on the upstream side of the conveyance path 18, and the roll press 50 can be provided on the downstream side.

[0079] The electrode sheet 10 is wound on the winding roll 17b after passing through the roll press 90. In this way, for the electrode sheet 10, the current collector 12 of the uncoated portion 12a is stretched by the roll press 50, and the current collector 12 of the coated portion 12b is stretched by the roll press 90. Thereby, the current collector 12 is elongated in both the uncoated portion 12a and the coated portion 12b, and the elongation of the current collector 12 is less likely to become uneven. As a result, the deformation of the elongated current collector 12 at the time of contraction is less likely to become uneven. Therefore, it is less likely to occur that, for example, wrinkles are formed in the uncoated portion 12a or the uncoated portion 12a is broken, and the quality of the electrode sheet 10 can be improved.

[0080] However, according to the present inventor's insight, in a case where the current collector of the electrode sheet is stretched using a roll having a rubber portion on the peripheral surface, the degree of elongation of the current collector can differ depending on the position of the rubber portion. In the roll pressing step, the current collector of the uncoated portion is stretched, but the closer to the end portion of the pressing roll, the smaller the deformation of the rubber portion. According to the present inventor's insight, in the rubber portion on the peripheral surface of the shaft portion of the pressing roll, the closer to the central portion, the larger the amount of deformation of the rubber at the time of compression of the uncoated portion, and the closer to the end portion, the smaller the amount of deformation of the rubber. Therefore, in a case where the outer end of the uncoated portion of the electrode sheet is compressed by the end portion of the rubber portion of the pressing roll, or the like, the outer end of the uncoated portion is sometimes more difficult to stretch than other portions of the uncoated portion.

[0081] In the above-described embodiment, the electrode sheet manufacturing apparatus 1 is provided with a conveying device 17, a support roller 60, a pressing roller 70, and a driving device (in this embodiment, a cylinder driving device 83) (refer to Figure 3 and Figure 4 ). The conveying device 17 conveys the long electrode sheet 10 along a predetermined conveying path 18. The support roller 60 is disposed at the conveying path 18 and supports the first face (lower face 10D) of the electrode sheet 10 conveyed along the conveying path 18 in the width direction. The pressing roller 70 is disposed in opposition to the support roller 60 at the second face (upper face 10U) of the electrode sheet 10. The cylinder driving device 83 presses the pressing roller 70 toward the support roller 60 with the electrode sheet 10 interposed therebetween. The electrode sheet 10 is provided with a current collector 12, an electrode active material layer 14, and a protective layer 16. The current collector 12 is composed of a metal foil. The electrode active material layer 14 is formed on the current collector 12. The protective layer 16 is formed in the longitudinal direction of the electrode active material layer 14. An uncoated portion 12a, which is not coated with the electrode active material layer 14 and the protective layer 16, is provided at the end portion of the electrode sheet 10. The pressing roller 70 is provided with a shaft portion 72 and a rubber portion 73. The rubber portion 73 is wound around the outer peripheral surface 72d of the shaft portion 72 at least in the region in contact with the uncoated portion 12a. The thickness of the rubber portion 73 at the position overlapping the outer end 12al of the uncoated portion 12a is thinner than the thickness of the rubber portion 73 at the region inward of the position overlapping the outer end 12al.

[0082] Figure 7 is a schematic view showing the relationship between the thickness of the rubber and the amount of deformation. Furthermore, Figure 7 is a view schematically illustrating that the amount of deformation of the rubber in the direction of the face varies depending on the thickness of the rubber, and does not necessarily reflect the actual object. According to the insight of the present inventor, as Figure 7As shown, even if the compression amount x is the same, the displacement amount yl of the thin rubber Al in the face direction (a direction orthogonal to the direction in which compression is performed) is greater than the displacement amount y2 of the thick rubber A2. If the electrode sheet manufacturing device 1 described above is used, the thickness of the rubber portion 73 at a position overlapping the outer end 12al is thinner than the thickness of the rubber portion 73 at a region on the inner side of the position overlapping the outer end 12al. The inner end 12a2 of the uncoated portion 12a can be pressed by the portion of the rubber portion 73 in which the thickness is thick, and the outer end 12al of the uncoated portion 12a can be pressed by the portion of the rubber portion 73 in which the thickness is thin. Thus, the deformation in the width direction of the rubber portion 73 at a position overlapping the outer end 12al of the uncoated portion 12a is greater than the deformation in the width direction of the rubber portion 73 at other positions of the uncoated portion 12a, such as the inner end 12a2 of the uncoated portion 12a. Therefore, in the roll-pressing process S6, the current collector 12 is easily elongated near the outer end 12al of the uncoated portion 12a. As a result, the difference in elongation between the portion near the outer end 12al of the uncoated portion 12a and the portion that is easily elongated in the roll-pressing process S6 (a portion of the uncoated portion 12a pressed by the substantially central portion of the pressing roller 70) easily becomes small. By making the difference in elongation of the current collector 12 small, it is difficult for the current collector 12 after being pressed to cause a defect such as a wrinkle or a break. Thus, it is possible to improve the quality of the electrode sheet 10.

[0083] In the above embodiment, the shaft portion 72 has a cylindrical portion 72a and a stepped portion 72b. The cylindrical portion 72a is cylindrical. The diameter of the stepped portion 72b is greater than the diameter of the cylindrical portion 72a. The rubber portion 73 has a thick portion 73a and a thin portion 73b. The thick portion 73a is wound around the outer peripheral surface of the cylindrical portion 72a. The thin portion 73b is wound around the outer peripheral surface of the stepped portion 72b. The stepped portion 72b is provided at a position overlapping the outer end 12al of the uncoated portion 12a. With this structure, the portion of the current collector 12 that is not easily elongated (the outer end 12al of the uncoated portion 12a) is made to be partially easily elongated. This effect is more effective when the thickness of the thick portion 73a is set to be 2 times or more and 3 times or less of the thickness of the thin portion 73b. In addition, this effect is more effective when the thickness of the rubber portion 63 and the thickness of the thick portion 73a are the same degree (for example, the thickness of the rubber portion 63 is 0.9 times or more and 1.1 times or less of the thickness of the thick portion 73a).

[0084] In the above embodiment, the shaft portion 72 has an inclined portion 72c that is inclined from the cylindrical portion 72a toward the stepped portion 72b. By changing the thickness of the rubber portion 73 on the outer peripheral surface of the stepped portion 72b in stages, it is possible to adjust the change in the elongation of the current collector 12 at a position corresponding to the inclined portion 72c. Further, the inclination angle of the inclined portion 72c is not particularly limited. In a case where it is desired to partially elongate the portion of the current collector 12 in which the protective layer 16 is formed, the inclination angle of the inclined portion 72c can be made larger. In a case where it is not necessary to partially elongate the portion of the current collector 12 in which the protective layer 16 is formed, the inclination angle of the inclined portion 72c can be made smaller. The angle of the inclined portion 72c can be appropriately set in accordance with the width of the protective layer 16 and the uncoated portion 12a, the thickness of the protective layer 16 and the current collector 12, the thickness of the rubber portion 73 corresponding to the cylindrical portion 72a and the stepped portion 72b, and the like.

[0085] In the above embodiment, the end portion of the rubber portion 73 is chamfered. Thereby, the electrode active material layer 14 is less likely to be compressed by the rubber portion 73. As a result, it is possible to reduce the load on the electrode active material layer 14.

[0086] Further, the size of the pressing roller that compresses the electrode sheet 10 is not limited to the above-described manner. Figure 8 is a schematic view of a roll press 150 according to another embodiment. Instead of the roll press 50, the roll press 150 can be used for the electrode sheet manufacturing apparatus 1.

[0087] 〈Roll press 150〉

[0088] As shown in Figure 8 , the roll press 150 includes the support roller 60 and a pressing roller 170. The structure of the pressing roller 170 is the same as that of the pressing roller 70 (see Figure 6 ) except for the length. The length of the pressing roller 170 is a degree of 2 times the width of the uncoated portion 12a. Although not particularly limited, the length of the pressing roller 170 is preferably a degree of 1.5 times or more and 2.5 times or less of the width of the uncoated portion 12a, and more preferably a degree of 1.8 times or more and 2.2 times or less. In this embodiment, the pressing roller 170 is disposed so that the central portion 173f1 of the rubber portion 173 overlaps the outer end 12a1 of the uncoated portion 12a. In the roll pressing process S6, the position overlapping the outer end 12a1 of the uncoated portion 12a is pressed by the central portion 173f1 of the rubber portion 173.

[0089] In the above embodiment, the length of the pressing roller 170 is longer than the width of the uncoated portion 12a. Therefore, the length of the rubber portion 173 is longer than the width of the uncoated portion 12a. The central portion 173f1 of the rubber portion 173 overlaps the outer end 12a1 of the uncoated portion 12a. Thereby, the uncoated portion 12a is compressed by the central portion 173f1 of the rubber portion 173. According to the inventor's insight, the closer to the central portion 173f1 of the rubber portion 73, the larger the deformation amount in the face direction (a direction orthogonal to the compressed direction). Therefore, the uncoated portion 12a is also easily elongated at the outer end 12a1. As a result, the deviation of the elongation in the uncoated portion 12a is easily reduced.

[0090] Further, the structure of the electrode sheet manufacturing apparatus 1 is not limited to the above embodiment. Figure 9 is a schematic view of a roll press 250 according to another embodiment. Figure 10 is a schematic view of a roll press 350 according to another embodiment. Instead of the roll press 50, the roll presses 250, 350 can be used for the electrode sheet manufacturing apparatus 1. In the roll presses 250, 350, the structures of the support rollers and the pressing rollers of the roll press are different, but the other structures can be the same.

[0091] 〈Roll press 250〉

[0092] As shown in Figure 9 , the roll press 250 includes the support rollers 160 and the pressing rollers 270. The support rollers 160 and the pressing rollers 270 can be driven by the press pressure adjustment mechanism 80 (refer to Figure 4 ).

[0093] 〈Support roller 160〉

[0094] As shown in Figure 9 , the support roller 160 (the main body portion 161 in this embodiment) includes the shaft portion 162 and the rubber portion 163.

[0095] 〈Shaft portion 162〉

[0096] The shaft portion 162 has a cylindrical portion 162a, a stepped portion 162b, and an inclined portion 162c. Although not shown, the cylindrical portion 162a is provided at both end portions of the support roller 160. The stepped portion 162b is sandwiched by the cylindrical portions 162a at both end portions.

[0097] The cylindrical portion 162a is a substantially cylindrical portion having a rotation axis set in a manner substantially parallel to the rotation axis of the support roller 160. The diameter of the cylindrical portion 162a is substantially constant. The cylindrical portion 162a is provided from the inside of the shaft portion 162 toward the outside. The cylindrical portion 162a is provided at least at a portion overlapping the uncoated portion 12a. The cylindrical portion 162a extends to a position inside the inner end 12a2 of the uncoated portion 12a.

[0098] The stepped portion 162b is a portion having a larger diameter than the cylindrical portion 162a. The stepped portion 162b is provided at a position inside the cylindrical portion 162a in the shaft portion 162. The stepped portion 162b is provided at least at a position overlapping with the outer end 12a1 of the uncoated portion 12a of the electrode sheet 10. In this embodiment, the outer end of the stepped portion 162b coincides with the outer end 12a1 of the uncoated portion 12a. The stepped portion 162b can also extend to a position outside the outer end 12a1. The stepped portion 162b is provided at a position overlapping with the protective layer 16.

[0099] The inclined portion 162c is a portion connecting the cylindrical portion 162a and the stepped portion 162b. The inclined portion 162c is a portion inclined from the cylindrical portion 162a toward the stepped portion 162b. In this embodiment, the inclined portion 162c is inclined in such a manner that the diameter increases from the cylindrical portion 162a toward the stepped portion 162b. In addition, the inclined portion 162c is not necessarily provided in the shaft portion 162. The rubber portion 163 is wound around the outer peripheral surface 162d of the shaft portion 162.

[0100] 〈Rubber portion 163〉

[0101] The rubber portion 163 is wound around the outer peripheral surface 162d of the shaft portion 162 at least in a region in contact with the uncoated portion 12a. The inner diameter of the rubber portion 163 corresponds to the outer diameter of the shaft portion 162. In this embodiment, the rubber portion 163 covers the entire outer peripheral surface (lateral peripheral surface) 162d of the shaft portion 162. In other words, the inner peripheral surface 163d of the rubber portion 163 follows the outer peripheral surface 162d of the shaft portion 162. The length of the rubber portion 163 is substantially the same as the length of the shaft portion 162. The rubber portion 163 is formed in a substantially cylindrical shape. The outer diameter of the rubber portion 163 is substantially constant. In this embodiment, the rubber portion 163 has a thick portion 163a, a thin portion 163b, and an inclined portion 163c. The thick portion 163a is wound around the cylindrical portion 162a of the shaft portion 162. The thin portion 163b is wound around the stepped portion 162b of the shaft portion 162. The inclined portion 163c is wound around the inclined portion 162c of the shaft portion 162.

[0102] The thick portion 163a is thicker than the thin portion 163b. The inclined portion 163c is inclined in such a manner that it becomes thinner from the thick portion 163a toward the thin portion 163b. The sum of the outer diameter of the cylindrical portion 162a and the thickness of the thick portion 163a is substantially the same as the sum of the outer diameter of the stepped portion 162b and the thickness of the thin portion 163b. The sum of the outer diameter of the inclined portion 162c and the inclined portion 163c is substantially constant in the axial direction of the backup roll 160. Therefore, the diameter of the backup roll 160 is substantially constant.

[0103] As described above, the step portion 162b overlaps with the outer end 12a1 of the uncoated portion 12a. The thin portion 163b of the rubber portion 163 is wound around the outer peripheral surface of the step portion 162b. Thereby, the thickness of the rubber portion at the position overlapping with the outer end 12a1 of the uncoated portion 12a is thinner than the thickness of the rubber portion at the area inside the position overlapping with the outer end 12a1. The electrode sheet 10 is supported by the outer peripheral surface 163f of the rubber portion 163. The uncoated portion 12a of the electrode sheet 10 is pressed by the press roller 170.

[0104] 〈Press roller 270〉

[0105] The press roller 270 (the main body portion 271 in this embodiment) has a shaft portion 272 and a rubber portion 273. The size of the press roller 270 and the position with respect to the electrode sheet 10 can be the same as those of the press roller 70 (refer to Figure 6 ), 170 (refer to Figure 8 ), and thus detailed description is omitted.

[0106] 〈Shaft portion 272〉

[0107] The shaft portion 272 is a substantially cylindrical member extending in the width direction of the electrode sheet 10. In this embodiment, the diameter of the shaft portion 272 is substantially constant. The rubber portion 273 is wound around the outer peripheral surface 272d of the shaft portion 272.

[0108] 〈Rubber portion 273〉

[0109] The rubber portion 273 is formed in a substantially cylindrical shape. The inner peripheral surface 273d of the rubber portion 273 corresponds to the outer peripheral surface 272d of the shaft portion 272. The inner diameter of the rubber portion 273 is the same as the outer diameter of the shaft portion 272. In this embodiment, the inner diameter of the rubber portion 273 is the same as the outer diameter of the shaft portion 272, and is substantially constant. The thickness of the rubber portion 273 is substantially constant except for both end portions along the axis of the press roller 270. The width direction end portion of the rubber portion 273 is chamfered, and the chamfered portion 273e is formed at the end portion. The structure of the chamfered portion 273e can be the same as that of the chamfered portion 73e (refer to Figure 6 ), and thus detailed description is omitted.

[0110] As described above, the support roller 160 includes a shaft portion 162 and a rubber portion 163. The rubber portion 163 is wound around the outer peripheral surface 162d of the shaft portion 162, at least in the area contacting the uncoated portion 12a. The thickness of the rubber portion 163 at the position where it overlaps with the outer end 12a1 of the uncoated portion 12a is thinner than the thickness of the rubber portion 163 in the region inside the position overlapping with the outer end 12a1. In this way, the relatively thinner portion of the rubber portion can also be provided on the support roller side. In this case, the uncoated portion 12a can be squeezed by the thicker portion of the rubber portion 163, and the protective layer 16 inside the inner end 12a2 of the uncoated portion 12a can be squeezed by the thinner portion of the rubber portion 163. Thus, with Figure 6 The same implementation method is shown, where the current collector 12, in and around where the protective layer 16 is formed, tends to elongate. As a result, the elongation deviation of the current collector 12 is easily reduced. This makes it less likely for the pressed current collector 12 to develop wrinkles, breakage, or other defects. Thus, the quality of the electrode sheet 10 can be improved.

[0111] <Roller Press 350>

[0112] like Figure 10 As shown, the roller press 350 includes a support roller 160 and a pressing roller 170. The support roller 160 and the pressing roller 170 can be pressed by a pressure adjustment mechanism 80 (see reference). Figure 4 Driven by the support roller 160. Figure 9 The support roller 160 shown has the same structure, and the pressing roller 170 is the same as... Figure 8 The pressing roller 170 shown has the same structure, so detailed description is omitted.

[0113] In this embodiment, in the support roller 160, the thickness of the rubber portion 163 at the position overlapping with the outer end 12a1 of the uncoated portion 12a is thinner than the thickness of the rubber portion 163 in the region further inward than the position overlapping with the outer end 12a1. Similarly, in the pressing roller 70, the thickness of the rubber portion 73 at the position overlapping with the outer end 12a1 of the uncoated portion 12a is thinner than the thickness of the rubber portion 73 in the region further inward than the position overlapping with the outer end 12a1. Therefore, the relatively thin rubber portions 73 and 163 of both the support roller 160 and the pressing roller 170 are compressed in the portion (protective layer 16) further inward than the inner end 12a2 of the uncoated portion 12a. This allows for a greater total deformation of the rubber portions 73 and 163. By increasing the deformation of the rubber portions 73 and 163, the current collector 12 is more easily elongated at the outer end 12a1 of the uncoated portion 12a.

[0114] In addition, Figure 10In the roll press 250 shown, the outer end of the thin portion 163b of the rubber portion 163 of the backup roll 160 and the outer end of the thin portion 73b of the rubber portion 73 of the press roll 170 are set at substantially the same position. However, the present application is not limited to this manner. In at least either the rubber portion 163 of the backup roll 160 or the rubber portion 73 of the press roll 170, it is sufficient that the thickness of the rubber portion at a position overlapping the outer end 12al of the uncoated portion 12a is made thinner than the thickness of the rubber portion at a region inside the position overlapping the outer end 12al. In this embodiment, the shaft portion 162 of the backup roll 160 is a second shaft portion, and the rubber portion 163 is a second rubber portion.

[0115] The above describes various embodiments of the technology disclosed herein. Unless otherwise specified, the embodiments and the like described herein do not limit the present application. In addition, the technology disclosed herein can be variously modified, and unless a particular problem arises, each component, each process mentioned herein can be appropriately omitted or appropriately combined. In addition, the present specification includes the disclosure described in each of the following items.

[0116] Item 1:

[0117] An electrode sheet manufacturing apparatus for manufacturing an electrode sheet,

[0118] The above electrode sheet has: a current collector composed of a long metal foil; an unformed portion provided at a predetermined position in the width direction of the current collector in the length direction; and an electrode active material layer formed on a portion of the current collector other than the unformed portion, wherein

[0119] The above electrode sheet manufacturing apparatus has:

[0120] a conveying device that conveys the electrode sheet along a predetermined conveying path;

[0121] a backup roll disposed in the conveying path and supporting a first surface of the electrode sheet conveyed along the conveying path in the width direction;

[0122] a press roll disposed in opposition to the backup roll on a second surface of the electrode sheet; and

[0123] a driving device that causes the press roll to press against the backup roll through the electrode sheet,

[0124] The above press roll has a shaft portion, and a rubber portion wound around an outer peripheral surface of the shaft portion at least in a region contacting the unformed portion,

[0125] The thickness of the rubber portion at a position overlapping with the outer end of the unformed portion is thinner than the thickness of the rubber portion at a region inward of the position overlapping with the outer end.

[0126] Item 2:

[0127] In the electrode sheet manufacturing apparatus according to Item 1,

[0128] The support roller has a second shaft portion, and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least at a region in contact with the unformed portion,

[0129] The thickness of the second rubber portion at a position overlapping with the outer end of the unformed portion is thinner than the thickness of the second rubber portion at a region inward of the position overlapping with the outer end.

[0130] Item 3:

[0131] An electrode sheet manufacturing apparatus for manufacturing an electrode sheet,

[0132] The electrode sheet has a current collector composed of a long metal foil, an unformed portion provided at a predetermined position in a width direction of the current collector in a length direction, and an electrode active material layer formed at a portion other than the unformed portion in the current collector, wherein

[0133] The electrode sheet manufacturing apparatus has:

[0134] a conveying device that conveys the electrode sheet along a predetermined conveying path;

[0135] a support roller disposed at the conveying path and supporting a first surface of the electrode sheet conveyed along the conveying path in a width direction;

[0136] a pressing roller disposed at a second surface of the electrode sheet in opposition to the support roller; and

[0137] a driving device that presses the pressing roller toward the support roller with the electrode sheet interposed therebetween.

[0138] The support roller has a shaft portion, and a rubber portion wound around an outer circumferential surface of the shaft portion at least at a region in contact with the unformed portion,

[0139] The thickness of the rubber portion at a position overlapping with the outer end of the unformed portion is thinner than the thickness of the rubber portion at a region inward of the position overlapping with the outer end.

[0140] Item 4:

[0141] The electrode sheet manufacturing apparatus according to any one of items 1 to 3,

[0142] The shaft portion has a cylindrical portion having a cylindrical shape, and a stepped portion having a diameter larger than the cylindrical portion,

[0143] The rubber portion has a thick portion wound around an outer periphery of the cylindrical portion, and a thin portion wound around an outer periphery of the stepped portion,

[0144] The stepped portion is provided at a position overlapping the outer end of the unformed portion.

[0145] Item 5:

[0146] The electrode sheet manufacturing apparatus according to item 4,

[0147] The shaft portion has a slanted portion slanted from the cylindrical portion toward the stepped portion.

[0148] Item 6:

[0149] The electrode sheet manufacturing apparatus according to item 4 or 5,

[0150] A thickness of the thick portion is more than twice and less than three times a thickness of the thin portion.

[0151] Item 7:

[0152] The electrode sheet manufacturing apparatus according to any one of items 4 to 6,

[0153] The support roller has a second shaft portion, and a second rubber portion wound around an outer periphery of the second shaft portion at least in a region in contact with the unformed portion,

[0154] A thickness of the second rubber portion is more than 0.9 times and less than 1.1 times a thickness of the thick portion.

[0155] Item 8:

[0156] The electrode sheet manufacturing apparatus according to any one of items 1 to 7,

[0157] An end portion of the rubber portion is chamfered.

[0158] Item 9:

[0159] The electrode sheet manufacturing apparatus according to any one of items 1 to 8,

[0160] A length of the rubber portion is longer than a width of the unformed portion,

[0161] A central portion of the rubber portion overlaps the outer end of the unformed portion.

[0162] Item 10:

[0163] A method of manufacturing an electrode sheet, comprising:

[0164] a preparation step of preparing an electrode sheet having: a current collector composed of a long metal foil; an unformed portion provided at a predetermined position in a width direction of the current collector in a length direction; and an electrode active material layer formed at a portion other than the unformed portion in the current collector; and

[0165] a rolling step of pressing the electrode sheet while conveying the electrode sheet along a predetermined conveying path by sandwiching the electrode sheet with a support roller and a pressing roller,

[0166] the pressing roller has a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region in contact with the unformed portion,

[0167] a thickness of the rubber portion at a position overlapping an outer end of the unformed portion is thinner than a thickness of the rubber portion at a region inward of the position overlapping the outer end,

[0168] in the rolling step, the electrode sheet is pressed using the pressing roller.

[0169] Item 11:

[0170] the method of manufacturing an electrode sheet according to item 10,

[0171] the support roller has a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region in contact with the unformed portion,

[0172] a thickness of the second rubber portion at a position overlapping the outer end of the unformed portion is thinner than a thickness of the second rubber portion at a region inward of the position overlapping the outer end.

[0173] Item 12:

[0174] a method of manufacturing an electrode sheet, comprising:

[0175] a preparation step of preparing an electrode sheet having: a current collector composed of a long metal foil; an unformed portion provided at a predetermined position in a width direction of the current collector in a length direction; and an electrode active material layer formed at a portion other than the unformed portion in the current collector; and

[0176] a rolling step of pressing the electrode sheet while conveying the electrode sheet along a predetermined conveying path by sandwiching the electrode sheet with a support roller and a pressing roller,

[0177] The support roller includes a shaft portion, and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region in contact with the unformed portion,

[0178] A thickness of the rubber portion at a position overlapping with the outer end of the unformed portion is thinner than a thickness of the rubber portion at a region inward of the position overlapping with the outer end,

[0179] In the rolling process, the electrode sheet is pressed using the support roller.

[0180] Item 13:

[0181] The manufacturing method of the electrode sheet according to any one of items 10 to 12,

[0182] The shaft portion has a cylindrical portion having a cylindrical shape, and a stepped portion having a diameter larger than the cylindrical portion,

[0183] The rubber portion has a thick portion wound around an outer circumferential surface of the cylindrical portion, and a thin portion wound around an outer circumferential surface of the stepped portion,

[0184] The stepped portion is provided at a position overlapping with the outer end of the unformed portion.

[0185] Item 14:

[0186] The manufacturing method of the electrode sheet according to item 13,

[0187] The shaft portion has an inclined surface inclined from the cylindrical portion toward the stepped portion.

[0188] Item 15:

[0189] The manufacturing method of the electrode sheet according to item 13 or 14,

[0190] A thickness of the thick portion is 2 times or more and 3 times or less of a thickness of the thin portion.

[0191] Item 16:

[0192] The manufacturing method of the electrode sheet according to any one of items 13 to 15,

[0193] The support roller includes a second shaft portion, and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region in contact with the unformed portion,

[0194] A thickness of the second rubber portion is 0.9 times or more and 1.1 times or less of a thickness of the thick portion.

[0195] Item 17:

[0196] The manufacturing method of the electrode sheet according to any one of items 10 to 16,

[0197] An end of the rubber portion is chamfered.

[0198] Item 18:

[0199] In the method of manufacturing the electrode sheet according to any one of items 10 to 17,

[0200] The length of the rubber portion is longer than the width of the unformed portion,

[0201] In the rolling process, the central portion of the rubber portion is pressed against a position overlapping the outer end of the unformed portion.

Claims

1. An electrode sheet manufacturing apparatus for manufacturing electrode sheets, The electrode sheet comprises: a current collector composed of a strip of metal foil; an unformed portion disposed along its length at a predetermined position in the width direction of the current collector; and an electrode active material layer formed in the current collector excluding the unformed portion. The electrode sheet manufacturing apparatus is characterized by having: A conveying device that conveys the electrode sheet along a predetermined conveying path; A support roller is disposed in the conveying path and supports the first surface of the electrode sheet conveyed along the conveying path in the width direction. The pressing roller is arranged on the second surface of the electrode sheet in a manner opposite to the support roller; as well as A driving device that causes the pressing roller to press against the support roller through the electrode plate. The pressing roller includes a shaft portion and a rubber portion wound around the outer peripheral surface of the shaft portion, at least in the area that contacts the unformed portion. The thickness of the rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the rubber portion in the region inside the position where it overlaps with the outer end.

2. The electrode sheet manufacturing apparatus according to claim 1, characterized in that, The support roller includes a second shaft portion and a second rubber portion wound around the outer peripheral surface of the second shaft portion, at least in the area that contacts the unformed portion. The thickness of the second rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the second rubber portion in the region inside the position where it overlaps with the outer end.

3. An electrode sheet manufacturing apparatus for manufacturing electrode sheets, The electrode sheet comprises: a current collector composed of a strip of metal foil; an unformed portion disposed along its length at a predetermined position in the width direction of the current collector; and an electrode active material layer formed in the current collector excluding the unformed portion. The electrode sheet manufacturing apparatus is characterized by having: A conveying device that conveys the electrode sheet along a predetermined conveying path; A support roller is disposed in the conveying path and supports the first surface of the electrode sheet conveyed along the conveying path in the width direction. The pressing roller is arranged on the second surface of the electrode sheet in a manner opposite to the support roller; as well as A driving device that causes the pressing roller to press against the support roller through the electrode plate. The support roller includes a shaft portion and a rubber portion wound around the outer peripheral surface of the shaft portion, at least in the area that contacts the unformed portion. The thickness of the rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the rubber portion in the region inside the position where it overlaps with the outer end.

4. The electrode sheet manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The shaft portion has a cylindrical portion and a stepped portion with a diameter larger than the cylindrical portion. The rubber portion has a thick portion wound around the outer peripheral surface of the cylindrical portion and a thin portion wound around the outer peripheral surface of the stepped portion. The stepped portion is positioned at a location overlapping the outer end of the unformed portion.

5. The electrode sheet manufacturing apparatus according to claim 4, characterized in that, The shaft portion has an inclined portion that slopes from the cylindrical portion toward the stepped portion.

6. The electrode sheet manufacturing apparatus according to claim 4, characterized in that, The thickness of the thick portion is more than twice and less than three times the thickness of the thin portion.

7. The electrode sheet manufacturing apparatus according to claim 4, characterized in that, The support roller includes a second shaft portion and a second rubber portion wound around the outer peripheral surface of the second shaft portion, at least in the area that contacts the unformed portion. The thickness of the second rubber portion is more than 0.9 times and less than 1.1 times the thickness of the thick portion.

8. The electrode sheet manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The ends of the rubber portion are chamfered.

9. The electrode sheet manufacturing apparatus according to any one of claims 1 to 3, characterized in that, The length of the rubber portion is longer than the width of the unformed portion. The central portion of the rubber portion overlaps with the outer end of the unformed portion.

10. A method for manufacturing an electrode sheet, characterized in that, Include: The preparation process includes preparing an electrode sheet, the electrode sheet comprising: a current collector composed of a strip of metal foil; an unformed portion positioned along its length at a predetermined location along its width in the current collector; and an electrode active material layer formed in the current collector excluding the unformed portion; and In the rolling process, the electrode sheet is conveyed along a predetermined conveying path while being pressed using support rollers and pressing rollers. The pressing roller includes a shaft portion and a rubber portion wound around the outer peripheral surface of the shaft portion, at least in the area that contacts the unformed portion. The thickness of the rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the rubber portion in the region further inward than the position where it overlaps with the outer end. In the rolling process, the pressing roller is used to press the electrode sheet.

11. The method for manufacturing an electrode sheet according to claim 10, characterized in that, The support roller includes a second shaft portion and a second rubber portion wound around the outer peripheral surface of the second shaft portion, at least in the area that contacts the unformed portion. The thickness of the second rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the second rubber portion in the region inside the position where it overlaps with the outer end.

12. A method for manufacturing an electrode sheet, characterized in that, Include: The preparation process includes preparing an electrode sheet, the electrode sheet comprising: a current collector composed of a strip of metal foil; an unformed portion positioned along its length at a predetermined location along its width in the current collector; and an electrode active material layer formed in the current collector excluding the unformed portion; and In the rolling process, the electrode sheet is conveyed along a predetermined conveying path while being pressed using support rollers and pressing rollers. The support roller includes a shaft portion and a rubber portion wound around the outer peripheral surface of the shaft portion, at least in the area that contacts the unformed portion. The thickness of the rubber portion at the position where it overlaps with the outer end of the unformed portion is thinner than the thickness of the rubber portion in the region further inward than the position where it overlaps with the outer end. In the rolling process, the support roller is used to press the electrode sheet.

13. The method for manufacturing an electrode sheet according to any one of claims 10 to 12, characterized in that, The shaft portion has a cylindrical portion and a stepped portion with a diameter larger than the cylindrical portion. The rubber portion has a thick portion wound around the outer peripheral surface of the cylindrical portion and a thin portion wound around the outer peripheral surface of the stepped portion. The stepped portion is positioned at a location overlapping the outer end of the unformed portion.

14. The method for manufacturing an electrode sheet according to claim 13, characterized in that, The shaft portion has an inclined surface that slopes from the cylindrical portion toward the stepped portion.

15. The method for manufacturing an electrode sheet according to claim 13, characterized in that, The thickness of the thick portion is more than twice and less than three times the thickness of the thin portion.

16. The method for manufacturing an electrode sheet according to claim 13, characterized in that, The support roller includes a second shaft portion and a second rubber portion wound around the outer peripheral surface of the second shaft portion, at least in the area that contacts the unformed portion. The thickness of the second rubber portion is more than 0.9 times and less than 1.1 times the thickness of the thick portion.

17. The method for manufacturing an electrode sheet according to any one of claims 10 to 12, characterized in that, The ends of the rubber portion are chamfered.

18. The method for manufacturing an electrode sheet according to any one of claims 10 to 12, characterized in that, The length of the rubber portion is longer than the width of the unformed portion. In the rolling process, the central portion of the rubber part is used to press the position that overlaps with the outer end of the unformed part.

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